Automatic Dependent Broadcast-Surveillance, or ADS-B, is a system
that allows pilots of ADS-B equipped aircraft to see other airplanes
that also have the gear, and it also sends its signals to ground
stations for monitoring by air traffic control. By 2020, it will be
mandatory for flight into congested airspace, but for now its main
application is in the wide open spaces of Alaska as part of the Capstone
Project. But while ADS-B is being portrayed as the main reason for a
sharp decline in accidents in those areas covered by Capstone, Cable
Wells, who flies for Air Excursions out of Gustavus, near Juneau,
tells AVweb it's the other gear that goes along with ADS-B that's making
the real difference.